Connect WizFi360 to AWS IoT using AT Command

Getting Started#

Hardware Requirement#

Desktop or laptop computer
MicroUSB cable
WizFi360-EVB-Shield

Software Requirement#

Preferred Serial Terminal (TeraTerm, YAT, etc.)
AWS Console account
Firmware v. 1.1.0.595 was used in this guide. Please contact us to receive this version.

AWS IoT Core preparation before start

Sign to console
Create a thing
Create a policy
important
Save certificates and key during creation. AWS root CA can be downloaded from here

Introduction#

AWS IoT provides secure, bi-directional communication between Internet-connected devices such as sensors, actuators, embedded micro-controllers, or smart appliances and the AWS Cloud. It is possible to connect to AWS via WizFi360 and send data using MQTT.

In this document we will provide guide how to connect to AWS services. Process consists of following steps:

Creation of AWS account
Creation & configuration of Thing in IoT Core
Connection & Message transfer

For this guide we used evaluation board WizFi360-EVB-Shield

Device preparation#

Hardware setting#

We are going to use WizFi360-EVB-Shield in standalone mode. MicroUSB cable will be used to connect through UART. Switch SW1 into ON position and connect MicroUSB.

Device connection#

Please check COM port number in Device Manager.

tip

If COM port cannot be found in Device Manager, please install drivers below.

Silicon Labs CP210x USB to UART Driver

AT Commands Description#

Please refer to AT Instruction Set to find information about all AT Commands. Below we will describe commands created for AWS connection.

1. Set SSL Certificate#

AT Command: AT+CASEND

Syntax:

Type	Command	Response
Set	AT+CASEND=<parameter>	OK

Defined values:

Parameter	Value
<parameter>	0: delete certificate 1: generate certificate

In order to check current certificate enter command AT+CASEND?

2. Set Private Key#

AT Command: AT+AWSPKSEND

Syntax:

Type	Command	Response
Set	AT+AWSPKSEND=<parameter>	OK

Defined values:

Parameter	Value
<parameter>	0: delete private key 1: save new private key

In order to check current key enter command AT+AWSPKSEND?

3. Set Certificate for Thing#

AT Command: AT+CLICASEND

Syntax:

Type	Command	Response
Set	AT+CLICASEND=<parameter>	OK

Defined values:

Parameter	Value
<parameter>	0: delete Certificate 1: save new certificate for Thing

In order to check current certificate enter command AT+CLICASEND?

4. Connect to AWS#

AT Command: AT+AWSCON

Syntax:

Type	Command	Response
Set	AT+AWSCON="<Thing ARN>"	CONNECT OK

important

Before connection to AWS certificates, MQTTTOPIC and MQTTSET shall be set.
Otherwise AT+AWSCON will return error.

Please note that AWSCON will return error when CIPMUX is set to 1.

Connection procedure#

Connect your device and launch terminal#

For connection use following configuration in terminal: 115200-8-N-1, None.

Connect WizFi360 to WiFi#

// Set module to station mode
AT+CWMODE_CUR=1

// Get AP list
AT+CWLAP 

// Connect to AP
AT+CWJAP_CUR="ssid","password" 

// Query WizFi360 IP address
AT+CIPSTA_CUR?

// SSL 설정. WizFi360 SSL인증서를 체크합니다. 체크 실패경우에 서버에 접속 불가능합니다.
AT+CIPSSLCCONF=2

Enter Certificate#

//Enter AWS Root CA
AT+CASEND=1

//Enter Private key
AT+AWSPKSEND=1

//Enter Client ceritificate
AT+CLICASEND=1

When saving certificate or private key, all lines shall be sent one by one from "Begin certificate" line till "End certificate" line.

Please refer to below image.

Connection to AWS#

// Shadow update and accepted links  should be copied from "Interact" menu in AWS Console
AT+MQTTTOPIC="shadow_update_link","shadow_accepted_link"

// User & password can be empty, thing name shall be entered 
AT+MQTTSET="","","thing_name",60

// Type your Rest API endpoint
AT+AWSCON="REST_API_endpoint" 

// Publish message
AT+MQTTPUB="{"state":{"reported":{"temp":"40","led":"on"}}}"  

// Disconnect from a broker
AT+MQTTDIS 

Can't find shadow links & Rest API endpoint? (Click here)

tip

Go to AWS IoT -> Manage -> Things -> Your thing -> Interact menu.
Check screenshot below.

Below is screenshot from terminal

Results#

Results can be checked in AWS -> AWS IoT -> Manage -> Things -> Shadow.
Since we subscribed to "updated" topic, when MQTT message is sent we can see reply message instantly.

Congratulations

WizFi360 is successfully connected to AWS!